textproduct: Albany

WHAT HAS CHANGED

Dropped high temperatures this afternoon due to abundant cloud cover through the next couple hours. Increased wind gusts tomorrow afternoon and Saturday. Increased snow amounts to up to 2-3" for portions of the Adirondacks Tomorrow afternoon and evening. Also, monitoring the next clipper system for Sunday, as recent guidance has trended slightly further south. If these trends continue, then a colder solution than currently forecast would be on the table.

KEY MESSAGES

1) 2 clipper systems, one tomorrow and the next Sunday/Sunday night, will bring snow to the high terrain of the Adirondacks, potentially resulting in slippery travel conditions. Plain rain is expected for the rest of the region.

DISCUSSION

Key Message 1: As of 1:55 PM EDT...Current GOES 16 WV imagery shows our region in a broad upper trough, with current radar imagery showing a few light snow showers/flurries across northern areas. These snow showers persist into the evening, but accumulations look very minimal, so no impact expected for most areas. While there are some breaks of sun to the west, we lowered expected daytime highs a few degrees from the NBM due to widespread cloud cover this morning up until now. Any lingering snow showers come to an end early tonight, with a ridge of sfc high pressure building overhead. High clouds will be on the increases ahead of the first in a series of clipper systems that will impact our region over the next several days...

Friday, an amplifying upper shortwave embedded in NW flow aloft will track towards our region, as will the collocated sfc low. Ahead of the sfc low, warm advection/isentropic lift will lead to precipitation across northern areas, with precipitation eventually spreading southeast with and ahead of the system's cold front as the center of low pressure tracks near or just north of I-90. Precipitation will likely begin as snow across the high terrain of the ADKs, but will change over to mainly rain by tomorrow evening. A general 1-3" is expected across the southern ADKs, with locally up to 4" for a few areas above 2000 ft in elevation. While these amounts will remain below advisory criteria, some slippery travel conditions will still be possible across the ADKs tomorrow afternoon into early evening. For the rest of the region, plain rain is expected. With showalter values near 0, a few rumbles of thunder can't be ruled out for portions of the Mid Hudson Valley. QPF amounts will range from up to around an inch in the southern ADKs where there will be some upslope enhancement to a quarter inch or less in the Hudson Valley from Albany southwards where downslope shadowing off the Catskills is expected with a 50+ kt southwesterly LLJ. Will also mention that given the strength of the low-level wind field, some gusts of up to 20-30 mph are expected in the typical S/SE channeled flow areas tomorrow ahead of the cold front.

Precipitation comes to an end Friday night, with the system's cold front dropping to the south of our region. High pressure then builds overhead resulting in tranquil weather through at least the day Saturday, and possible much of Saturday night. With the cold front to our south, we lowered temperatures a few to several degrees from the NBM for areas north of I-90 on Saturday. Highs will range from upper 30s in the ADKs to upper 50s near I-84.

Saturday night, Another amplifying upper shortwave within the NW flow aloft will track towards our region from southern Canada, with an associated deepening sfc low tracking from the northern Plains towards the Ohio Valley and Great Lakes. This will help to lift the aforementioned cold front that stalled to our south will back north as a warm front. How far north the warm front gets will play a major role in our weather for Sunday. As this strengthening sfc low helps to lift the warm front northwards Saturday night/early Sunday morning, we'll likely see some snow showers across northern areas.

Sunday, forecast confidence lowers drastically. While the GFS seems like an outlier relative to other guidance, most of today's 12z guidance has trended to show a ridge of sfc high pressure building into southern Canada slightly quicker than earlier guidance. This would help reinforce the low-level cold air to the north of the warm front, and would help slow the warm front's northward progression. Given that this next sfc low will track along the low-level thermal gradient, guidance has trended slightly further south the the track of the sfc low itself. The current forecast would still result in mainly rain for much of the area Sunday afternoon or Sunday night, but northern areas could see additional light snow accumulations. Should this colder trend continue, then snowfall amounts would likely end up higher than the current forecast across the ADKs and possibly southern Greens. Will also mention that moisture looks more impressive with this second system, as PWATs increase to around 1" which is 2-3 standard deviations above normal per the latest NAEFS. The location of the sfc front will also have a significant impact on temperatures Sunday: areas south of the front will likely be in the upper 50s to mid 60s with generally dry conditions through much of the day, while areas near and north of the front may be stuck in the 30s with more clouds and precip around.

Regardless of the track of this system, there is decent agreement that the best chances for precip will be late Sunday afternoon and night, with rain/snow showers tapering off through the day Monday. There is also good agreement for a strengthening pressure gradient to bring some gusty winds behind the system Monday. We collaborated with WPC to have Monday's wind gusts bumped up, but believe that the current forecast for max gusts of 20-25 kt will likely need to be further increased with subsequent forecast packages. Once this system departs, confidence is fairly high for another shot of cold air into the region, although temperatures will likely end up warmer than the past couple days have been here. Fairly tranquil weather is expected Tuesday and Wednesday as high pressure builds over the region, but another upper shortwave within the continued NW flow aloft could bring additional chances for some light rain/snow showers towards the very end of the forecast period.

AVIATION /06Z FRIDAY THROUGH TUESDAY/

Through 06Z/Sat, mainly VFR conditions are expected through late morning. As a warm front approaches from the west this afternoon, rain is expected to overspread the TAF sites from NW to SE between 18Z-22Z/Fri. Periods of MVFR/IFR (mainly for Vsbys) are expected as the rain tracks through, especially within any pockets of moderate rain. The rain could briefly be mixed with snow at KGFL at the start. The rain should taper off from NW to SE between 23Z Fri-03Z/Sat, however lingering low clouds and mist/drizzle should keep flight conditions MVFR/IFR through at least 06Z/Sat.

Light/variable winds will become south to southeast and increase to 8-15 KT by early afternoon with some gusts of 25-30 KT possible, especially at KALB. South to southeast winds will then gradually decrease to 8-12 KT toward and after sunset, eventually shifting into the west to northwest at 5-10 KT toward and after 06Z/Sat.

Outlook...

Saturday Night: Moderate Operational Impact. Chance of RA...SN. Sunday: High Operational Impact. Likely RA...SN. Sunday Night: Moderate Operational Impact. Likely RA...SN. Monday: Moderate Operational Impact. Chance of RA...SN. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.